EP3001823B1 - Device and method for sharpening rotary knives - Google Patents

Description

The present invention relates to a device for grinding rotary knives, in particular sickle or circular knives, in particular for machines for slicing food products, such as sausage, ham, cheese or the like.

The slicing machine may in particular be a high-performance slicer.

The invention also relates to methods for grinding rotary blades.

Rotary knives may wear and become dull so they need to be ground. Known rotary knife sharpeners use a copying plate which is a copy of the type of knife to be ground. In order to grind a rotary knife belonging to the knife type, the cutting edge present on the copying plate is traversed. This "Abfahrbewegung" is transmitted via a copying device to a grinding tool that moves the cutting edge of the rotary blade according to and grinds the rotary blade.

The disadvantage here is that - especially when several different types of knives are to be ground with a grinding device - a separate copy plate must be maintained for each type of knife. This not only costs. Rather, the time required to grind a rotary blade can be increased by the fact that for the rotary blade to be ground required copy plate must be attached to the grinder before it can be started with the grinding. Another disadvantage is that a copy plate is only a "copy" of an unused rotary blade. Use-related wear and / or peculiarities on the cutting edge of the rotary blade to be ground are therefore not taken into account in the copying plate. This can lead to a non-optimal grinding result.

Conventional grinders may further grind only one-piece rotary knives. On the other hand, if the rotary knives are divided into segments, conventional grinding devices can not be used.

The publication EP 2 532 477 A2 discloses an apparatus and method for grinding rotary blades, the apparatus having a receptacle which engages a receiving aperture of an integrally formed rotary blade for rotatably supporting it.

In the publication DE 20 2013 005 156 U1 there is disclosed an apparatus for grinding at least one knife comprising a grinding unit with a guide member which engages a template. In one embodiment, the template is virtually executed as a data set, which is associated with the contour of the cutting edge of the knife to be ground. Each knife type is assigned a barcode that can be used to automatically use the template that matches the type of knife.

The present invention has for its object to provide a way by which a, in particular segmented, rotary knife can be ground in an improved manner.

The object is achieved by a device and a method in each case with the features of the independent claims.

According to the invention, the device is designed for grinding rotary blades, which have at least two segments.

In principle, a rotary blade can have any number of segments, for example two, three, four, five or more segments. In particular, therefore, there is no one-piece rotary blade.

As a segment, any arbitrarily shaped portion of the rotary blade can be considered in particular, which is separated from the rest of the knife, wherein all segments together form the rotary blade. The segments of a knife may in particular have the same shape and be designed, for example, the same.

The rotary knife may in particular be a sickle knife with exactly one at least approximately spiral-shaped outer or cutting geometry. Such a geometry is hereinafter also referred to in the description and in the claims for the sake of simplicity also shortened as "spiral", i. when hereinafter in the description or in the claims of a "spiral" or a "spiral shape" is mentioned, this is generally an at least approximately spiral-shaped outer or cutting geometry to understand.

For example, the spiral may also be referred to as a sickle or wing. It can thus be e.g. a conventional sickle knife with a single spiral be divided into several segments.

Furthermore, in particular sickle blades with several, for example, two, three, four, five or more, spirals are possible. Multi-spiral sickle knives are also referred to as multi-blade sickle knives or multi-spiral knives.

Preferably, each segment may have exactly one spiral.

In particular, a cutting edge can run along one or each spiral.

It is also possible that a circular knife, which by definition has no spiral, is divided into several segments. In a circular knife with two segments, each segment may be shaped in particular semicircular.

The device according to the invention comprises at least two receptacles, to each of which a segment can be attached. There is a separate recording for each segment. The segments can in particular be fastened individually.

The attachment may in particular comprise a fixation in the circumferential direction and / or a centering of the segments.

The device comprises at least one grinding tool, wherein the grinding tool and the segment mounted in the receptacle are movable relative to each other in such a way that an edge running on the circumference of the segment can be ground by the grinding tool.

In particular, a pivoting device may be provided for the grinding tool, wherein the pivoting device may be configured such that the grinding tool is pivotable about a pivot axis which passes through a grinding point at which the cutting edge and the grinding tool touch during the grinding process. Preferably, the grinding tool may comprise a grinding wheel which contacts the cutting edge at the grinding point and is pivotable about the pivot axis.

Due to the pivotability of the grinding wheel to the running through the grinding point pivot axis of the grinding angle can be adjusted in a simple manner and in particular also changed during the grinding process, being designated as the grinding angle, the angle between the grinding wheel and the cutting edge. It is thus possible, for example, to set the grinding angle during the grinding process as a function of a determined or predetermined cutting profile.

The grinding tool may include a Abziehscheibe which forms at least approximately together with the grinding wheel a V-shaped receptacle for the segment and the blade touches at a Abziehpunkt. Through the honing wheel For example, burrs resulting from the grinding process can be removed from the cutting edge. It is advantageous if the Abziehscheibe is pivotable together with the grinding wheel and / or independently of the grinding wheel about the pivot axis, so that the peel angle, which encloses the Abziehscheibe with the cutting edge, in particular changed during the grinding process and, for example, depending on the determined cutting edge can be adjusted. It is particularly advantageous if the draw-off point also runs through the pivot axis, since then the draw-off point does not or only slightly "migrates" onto the draw-off disk when it is pivoted.

In particular, the segment and the grinding tool can be positioned relative to one another such that, in particular during the grinding process, the pivot axis is aligned tangentially to the cutting edge present at the respective grinding point. In this way, a particularly good grinding result is achieved.

The apparatus further comprises a measuring device for determining the course of the cutting edge of at least one segment and a controller, which is designed to use the determined cutting edge profile for controlling the relative movement between the grinding tool and at least one segment.

In particular, the measuring device can be designed to record a cutting edge or another feature of the segment that corresponds to the cutting profile and / or that allows derivation of the cutting edge profile as the cutting edge profile. The cutting edge can be detected particularly easily, for example by a light barrier, which favors the determination of the cutting edge profile. The feature which allows derivation of the cutting profile can be, for example, a plurality of elevations or an edge at the transition from a cutting area to a further inward area of the knife, which on one side of the knife body is the course are arranged following the cutting edge or is, so that the cutting edge profile can be derived from the detected course of the elevations or the edge. A knife with such surveys is for example from the DE 10 2009 006 912 A1 known.

The measuring device can preferably work without contact. As a result, the measuring device can be protected against contamination and wear.

In particular, the measuring device may have a detection range with which only a portion of the cutting edge can be detected. As a result, the position of the section can be determined relatively accurately and the cutting edge profile can be determined with sufficient accuracy from a plurality of detected positions of a plurality of cutting sections lying along the cutting edge profile. A selective detection of the cutting edge can also be provided so that the cutting edge profile can be determined from a plurality of points detected in this way, for example by interpolation.

The measuring device and the segment can preferably be movable relative to one another in such a way that the cutting edge can be moved through the detection area of the measuring device and can be detected continuously or in sections. As a result, the cutting edge profile can be detected easily and quickly in the case of selective or sectional detection of the cutting edge.

In particular, the measuring device can be designed to be movable. In this way it is possible, by moving the measuring device, to detect a section of the cutting edge that crosses the travel path as soon as it comes into the detection range of the measuring device.

Preferably, the measuring device may comprise a light barrier, in particular a fork light barrier. This allows a reliable measuring device can be realized simultaneously cost.

In particular, the measuring device can be designed to determine the position at which the light barrier is interrupted or released by a section of the cutting edge, as a measured value for the position of this section. As a result, for example, the position of a section detected by the light barrier relative to a travel path of the light barrier can be detected. This is advantageous because the travel of the light barrier can be measured particularly easily, for example by means of an encoder which is coupled to a drive for moving the light barrier.

In a particularly advantageous manner, the measuring device can be designed to use the set of all positions thus detected at least as the basis for the cutting edge profile. In this case, the positions can be assumed directly as a cutting profile or additional positions can be calculated, for example by interpolation, so that the cutting edge profile can be determined with high accuracy.

Preferably, the segment can be moved and the measuring device can be designed to determine the position of the segment. This makes it possible to detect the positions in each case depending on the position of the segment and to determine the cutting edge profile, for example in the form of pairs of values, wherein a pair of values a detected position of a portion of the cutting edge, ie a part of the cutting edge profile, and the associated position of the Segment includes.

The course of the cutting edge can be determined particularly easily if the segment can be rotated about an axis of rotation provided for the cutting operation and the measuring device can be moved linearly such that for a plurality of rotational positions of the segment by means of the measuring device, the position of a portion of the cutting edge of the segment can be determined.

In the device according to the invention, it is possible to determine the cutting edge profile of at least one segment before the grinding process. In particular, the cutting profile of each segment can be determined.

Copy plates are therefore no longer needed. In addition, segment-specific wear and / or deviations of the cutting edge profile from the "ideal" shape of a still unused knife or segment can be taken into account in this way, so that an optimal grinding result can be achieved.

Within the scope of this disclosure, "cutting profile" is also understood to mean the course of the cutting angle, which can vary along the circumference of the knife, while the cutting edge is e.g. lies on a circle.

The grinding device according to the invention can also be used to grind rotary knives having a plurality of segments. In contrast to grinding devices for grinding one-piece rotary knives, no one-piece rotary knife is received in the receptacle. There is a separate recording for each segment. Preferably, a single grinding tool is provided, which grinds all segments. However, it is also possible to provide a plurality of grinding tools, in particular one grinding tool per segment.

The control is also explicitly designed to grind individual segments, for example not a rotary knife as a whole. The controller must in this case be explicitly matched to the respective, in particular also differently shaped, segments.

The term "grinding" on the one hand to understand a first-time application of a cutting edge and on the other hand, a regrinding, such as blunted segments. Thus, the invention also explicitly relates to a device and method for regrinding rotary blades or segments of rotary blades.

In particular, the grinding can be carried out at least partially in a position in which the segments are arranged directly next to one another. The segments can be stretched flat and processed together. The processing of the segments can be coordinated with each other.

Further developments of the invention can be found in the dependent claims, the description and the accompanying drawings.

In one embodiment, the controller is adapted to operate on equal segments, i. in particular segments with the same cutting geometry, preferably the same cutting edge profile and / or the same cutting angle or the same cutting angle course, preferably with the same basic structure, the determined using a first segment edge profile to control the relative movement between the grinding tool and at least one other segment to use.

Equally executed segments can result especially in circular knives or multispiral knives. In the case of circular knives, a segment may, for example, be designed as a circular segment. If the circular blade comprises exactly two segments, the segments can each have a semicircular shape. In the case of multispiral knives, the segments of the same design can be designed in particular as a spiral.

It is therefore initially possible to determine the cutting edge profile of a first segment with the aid of the measuring device. The course of the cutting edge can in particular be stored and used, for example, for a further segment. A determination of the course of the cutting edge of another segment is thus not necessary in particular. This can save time. The grinding process can thus be made efficient.

In particular, a one-time determined cutting profile can be used for all segments of the same design. Preferably equal segments can thus be ground according to the same criteria.

According to a further embodiment, a reading and / or writing device is provided, which is designed to describe data, in particular each memory device coupled to a respective segment and / or a memory device of the grinding device, preferably an RFID transponder, and / or or read the data stored on it.

Each segment can preferably comprise a memory device, in particular an RFID transponder or RFID chip. The storage device may in particular be attached to a side surface of the segment.

The grinding device itself may also comprise a storage device.

Basically, any storage media such as chips, memory cards, flash memory, USB sticks or SSD storage are possible. In principle, the data information can also be contained in barcodes or QR codes, which can be applied in particular to the segments.

The data may in particular include the course of the respective cutting edge or data dependent on this course. For example, the course of the cutting edge of the first segment can be saved.

The data may, for example, represent the control data for the grinding tool.

Furthermore, the data may include cutting parameters, for example the cutting edge angle. In addition, the information may be included in the data, as often a corresponding segment or a rotary knife has already been ground. Also, for example, balance data of the respective segments can be stored.

It can be achieved by means of the memory device assignment of the individual segments. A pairing of the respective segments can be ensured in this way.

In particular, the data determined on the basis of the first segment, which relate to the cutting profile of the first segment, can be transmitted to the storage device of the grinding device and / or to the storage device of at least one further segment. In this way, cutting profiles can be stored on segments whose cutting edge profile itself has not been determined. According to the invention, a separate receptacle is provided for each segment, the receptacles and / or the segments held in the receptacles being spaced apart from each other during the grinding process.

When grinding one-piece sickle blade, for example, the disadvantage that not the entire peripheral area can be ground. For example, e.g. in the vicinity of an edge of the spiral, which does not serve as a cutting area, a so-called discharge area is provided, which can not be achieved by a conventional grinding device.

Such a discharge area can be omitted in a separate processing of the segments, since the segments can be ground independently. Thus, cutting ranges of 360 ° are possible. Depending on the geometry of the segments, the cutting area can also be greater than 360 °.

In this case, the segments can be ground in particular spatially separated from each other. For example, the segments received in a grinding device may be spaced apart from each other.

Alternatively, it is also possible to grind the segments one after the other.

Preferably, segments of the same design, which are ground in a spaced-apart position, can be ground on the basis of data determined only on one segment.

The recordings can in particular be permanently separated from each other locally.

In a preferred variant, the receptacles are assigned to each other and / or relative to each other adjustable. In this case, the receptacles may preferably initially lie directly next to each other, so that the individual segments can be mounted together. Subsequently, if necessary, a Cutting edge course are determined. The recordings can then be moved apart. Here it is possible to adjust all recordings. Alternatively, a recording remain stationary while at least one further recording is adjusted. The movement of a recording can take place both in the plane of the rotary blade and vertically thereto, ie in the axial direction. The movements and distances are selected according to the measuring and grinding tools.

Also in this adjusted position, if necessary, the cutting edge profile of at least one of the segments can be determined. The determination of the cutting profile does not have to be done before adjusting the recordings.

The grinding itself is preferably carried out in a position in which the receptacles are spaced apart.

At least partially, the grinding can also take place in a position in which the receptacles and thus the segments are arranged directly next to each other in order to match the segments to one another.

To dismantle the segments, the recordings can be adjusted to each other again. The individual segments can then be removed again in particular together.

The invention also relates to a method for grinding rotary knives, in particular sickle or circular knives, in particular for a machine for slicing food products, for example sausage, ham, cheese or the like.

The device for slicing food products may in particular be a high-performance slicer.

According to the invention, rotary knives are ground, which have at least two segments. In this case, a grinding device according to the invention can be used.

First, the course of a cutting edge of at least one segment is determined and at least one segment is then ground during a relative movement between the segment and a grinding tool. The relative movement between the segment and the grinding tool is controlled on the basis of the determined cutting profile.

The segments can in this case, in particular jointly, be placed on a common receptacle. Also, the segments can be put together on different shots. Preferably, the segments are hereby clamped plane.

Thus, for example, the segments may be timed, e.g. by means of a handling device, are mounted on the grinding device.

If the receptacles for the respective segments are spaced from each other, the segments can for example also be spatially separated from each other. For assembly or disassembly, a handling device may be used which comprises a plurality of sections.

It is also possible to successively set up the segments on one, in particular the same, receptacle. The segments can therefore be ground consecutively in time.

According to one embodiment, the segments are held on different receptacles, wherein the receptacles are adjusted relative to each other to provide a distance between the segments during the course of the cutting process and / or during grinding.

The segments can be placed here successively or simultaneously on the different shots. Subsequently, for example, the cutting edge profile, in particular of all segments can be determined. If the segments are the same, only the edge profile of a segment can be determined.

Then the shots can be adjusted relative to each other. In particular, the recordings are moved apart, wherein all recordings or only one of the recordings can be adjusted relative to the other recording. For adjusting the recordings, an electric drive is provided in particular. However, the adjustment can in principle also be done manually or pneumatically. In this case, both variable, preferably predetermined by the controller, positions and - alternatively - fixed positions are conceivable, for example, a clamping position and a machining position.

The determination of the cutting edge profile can also take place only when the segments are separated from each other. A determination of the cutting edge profile can also be dispensed with altogether, if identical segments are used, of which the cutting profile is already known and stored, for example, in a memory device, in particular of the segments.

If a distance between the segments is set, the segments can be ground. In this way, even with sickle blades cutting areas of 360 ° and greater can be achieved, since no outlet area is necessary, such as in one-piece sickle blades.

After sanding, the shots can be adjusted to each other again. Depending on the design, one of the receptacles can be stationary while at least one other receptacle is being moved. If the segments are again arranged next to one another, they can be removed from the receptacles by means of a handling device.

In a variable design of the handling device, however, the segments can also be removed when the segments are spaced apart.

It may be a handling device for attaching a rotary knife comprising at least two segments, in particular a sickle or circular blade, provided on a blade holder, preferably on a device for grinding rotary blades or a device for cutting food products with at least two sections, wherein each section for Receiving a segment is formed.

Such a handling device may also be referred to as a knife guard and, in particular, in addition to the holding function, also fulfill a number of other functions.

Preferably, the number of sections may correspond to the number of segments.

In this way, the individual segments can be transported independently. The weight to be transported can be considerably reduced because the knife does not have to be moved as a whole. Also, the assembly and disassembly of the individual segments on the blade holder by means of the respective sections of the handling device independently respectively. So must also be held during assembly or disassembly preferably only one segment.

The handling is significantly improved according to the invention, since not the entire knife has to be mounted, dismantled or transported all at once.

By dividing the handling device into sections, the individual segments may be e.g. be placed on a grinding device at any position, in particular on spaced apart blade receptacles, separated from each other. In particular, the individual segments can also be removed independently of one another.

Preferably, the cutting edges of the respective segments can be received in the sections. In this case, the sections can thus serve in particular as a blade guard.

Each section can be adapted to the contour and / or size of the respective segment. For example, in the case of a circular blade, the sections can be shaped as circular segments. In a sickle blade, at least a portion may have a crescent-shaped structure.

For example, in the case of circular knives or sickle knives having multiple spirals, the cuts can be made the same. Also, a portion greater than at least another portion may be formed. This is particularly the case when a sickle knife with only one spiral is divided into two segments. The section which accommodates the spiral can in this case in particular be larger than the section which accommodates the segment which contains no spiral. The sections may in this case be designed in particular as semicircles with mutually different radii.

The sections can be detachably connected to one another, in particular by means of a screw, latch, slide and / or clamping device. In principle, any composite devices are possible.

The sections can thus be bolted together, for example. Also a bayonet closure is e.g. possible. Furthermore, a magnetic connection of the sections may be provided.

Preferably, the sections can be connected to each other without tools and / or separated again.

The sections can be connected to each other in particular for storage. A clear assignment of the recorded segments in the segments is ensured.

The segments can preferably be reused in this way in pairs.

The assembly or disassembly can be done by the detachable connection in particular together or individually.

The sections can be connected or connected to each other in a position in which they are arranged, in particular flush, adjacent in a plane.

Alternatively, the sections can be connected or connected to one another in a position in which they are arranged at least partially overlapping.

The individual sections may in particular be located one above the other in different planes. Preferably, the sections may be arranged completely overlapping.

An overlapping arrangement allows in particular a space-saving storage.

For this aspect of a handling device, protection is also claimed separately and independently of other aspects of the device described herein or the methods described herein.

According to a further embodiment, the same segments are ground successively. The segments can be placed successively or together on a recording or on different recordings. First, a cutting profile of a first segment is determined on the basis of a first segment. This cutting profile is used to control the relative movement between the grinding train and at least one other segment.

It is therefore initially possible to determine the course of the edge of the first segment and subsequently to sand the first segment on the basis of the determined cutting profile. Then a further segment can be ground on the basis of the data determined by the first segment. The further segment can in this case be placed on the same receptacle, in particular after removal of the first segment. It is also possible that the further segment is placed on a separate receptacle and ground there. In particular, the segments may be spaced from each other here.

The fact that only a cutting edge profile of a segment is determined, the cutting process can be optimized. In particular, this time can be saved because a renewed measurement of a preferably at least substantially identical edge profile is eliminated.

In an alternative embodiment, differently shaped segments can each be ground with different grinding parameters.

In particular, the differently shaped segments can also have an identical base structure. The difference between the segments results from the different grinding parameters.

The different segments can be placed one after the other or together on one or on different shots.

In particular, a separate edge profile can be determined for each segment. Alternatively, the cutting profile can also be removed, for example, from a storage device.

The cutting parameters may in particular include the cutting edge angle and / or the course of the cutting edge.

The cutting angle is the angle between a cutting plane perpendicular to the axis of rotation of the knife and a plane tangent to the cutting surface through any point on the cutting edge.

The cutting angle determines, on the one hand, the influence on the product to be sliced and, on the other hand, the manner of depositing the respectively separated product slice by the rotary knife.

In practice, the size of the cutting angle is chosen depending on the product and application specific conditions. The edge angle constant along the cutting edge always represents a compromise with regard to the products to be sliced. A too large cutting angle, ie an edge surface that is too steep, should be avoided as far as possible This would put too much pressure on the product and thus expose the product to unacceptable compression. In contrast, a small cutting angle, ie a relatively flat cutting surface, results in gentle, gentle cuts that do not unnecessarily compress the product. However, can not be achieved with such a flat set rotary meter, the desired in most cases storage behavior with respect to each separated product slices. In particular, with a rotary blade set too flat, the product slices can not be "wedged" in the desired manner.

According to a development, the differently shaped segments are ground in such a way that they each have a circumferentially varying, in particular continuously increasing or decreasing cutting angle. In particular, the cutting angle as a whole, i. the cutting angle of the rotary blade, steadily increase.

There is thus a targeted change in the size of the cutting angle in the circumferential direction of the rotary blade. Of course, such changes do not include any production-related inaccuracies which lead to deviations from a constant desired angle. Rather, according to the invention, the cutting edge angle of the individual segments is selectively varied to a relevant extent along the cutting edge, which has noticeable effects in the cutting operation, in particular on the extent of the product upsets caused by the rotary knife and on the manner of product placement effected by the knife.

In particular, the size of the cutting edge angle can be adapted to the course of the cutting process. For each circumferential region of the rotary blade, the cutting edge angle can be chosen depending on which This cooperating peripheral region during the cutting process with the respective product.

Crescents with only one spiral are inserted in such a way that at the beginning of a cutting process they are immersed in the product with a circumferential area at which the radius - i.e. the radius -. the distance of the cutting edge from the axis of rotation of the knife - is smallest. From a certain angle of rotation, which corresponds to a certain peripheral region of the cutting edge, the dipping process of the knife is completed in the product. Until the end of the cutting process, the rotary blade moves through the product, wherein the radius due to the particular spiral-like course of the cutting edge with respect to the axis of rotation increases steadily. These conditions can be used to determine the size of the cutting angle as a function of the angle of rotation or the peripheral region - e.g. relative to the dip angle or immersion area - to optimize the overall cutting process. Basically, however, the setting options are no limits. Depending on the nature of the products to be sliced and the circumstances of the particular application, the rotary blades can be optimized individually due to the variability of the cutting edge angle according to the invention.

Preferably, the pivoting device for the grinding tool on at least one pivot bearing whose axis of rotation coincides with the pivot axis of the grinding tool. Thereby, the grinding device can be pivoted in a simple manner by means of the pivot bearing during grinding and the grinding angle between the grinding wheel and the cutting edge can be optimally adapted. This is particularly advantageous in rotary knives whose cutting edge has a variable cutting angle.

A one-piece knife with variable cutting angle is for example from the EP 2 162 266 B1 known. The provision of a pivot bearing, the one with the Has pivot axis coincident axis of rotation, has the advantage that the grinding tool by a rotational axis occurring about the rotational movement extremely precise and störungsunanfällig pivoted around the grinding point and thus the grinding angle can be adjusted during the grinding process in a simple manner.

In particular, the cutting edges of the segments are ground in such a way that they are adapted to one another. Thus, a cutting edge of the rotary blade with a continuously increasing or decreasing cutting edge angle preferably results.

In particular, the cutting edges of the segments can be adapted to each other such that the largest cutting angle of a segment is less than or equal to the smallest cutting angle of the adjacent segment.

For example, it can be provided that the rotary blade has a designated direction of rotation, wherein the cutting angle increases counter to the direction of rotation over all the edges of the segments. In other words, during the cutting operation, the cutting angle increases, i. the cutting edge on the outside of the blade, which is radially outwardly bounded by the cutting edge, becomes progressively steeper during the cutting process.

In particular, the cutting angle can increase with increasing radial distance of the cutting edge of the rotation axis. Preferably, the cutting edge may have an immersion region, with which the rotary blade, when used as intended, is immersed in a product to be sliced during the cutting operation, wherein the cutting angle is smallest in the immersion region.

In particular, the change of the cutting angle can be done without the formation of steps in the cutting surface.

The cutting angle may e.g. in a range of about 15 ° to 30 °, preferably about 20 ° to 30 ° vary.

Preferably, the cutting surface may have a width that varies depending on the size of the cutting angle. The width may e.g. vary in a range of about 0.5 mm to 1.5 mm.

In particular, the cutting edge of the rotary blade can extend overall over an angle which is between 180 ° and 360 °. Even angles greater than 360 ° are possible with a corresponding design of the spiral.

According to an alternative embodiment, the differently shaped segments are ground such that they each have a mutually different, at least substantially constant cutting angle.

For example, one segment may have a cutting angle of about 15 °, while another segment may have a cutting angle of about 20 °.

The fact that the cutting edges of the individual segments each have a constant angle, the grinding process can be realized in a simple manner. So the grinding angle does not have to be changed permanently. The cutting angle of the individual segments can be adapted to the respective cutting phase.

The angle may, for example, be constant over a range of 80%, 90% or 95% of the total cutting edge of the respective segment. At an area, on the edge of a segment adjacent to a cutting edge of another segment, a deviating, variable angle can be provided in this case.

According to another embodiment, a smooth transition between the segments is ground with different cutting angles.

When cutting can thus be realized at least substantially smooth transition between the individual segments. The different cutting angle can be adapted in the region of the transition in particular at least substantially to each other.

To realize a smooth transition, for example, both adjacent segments can be matched to each other. However, it is also possible to adapt only one of the segments to the adjacent segment.

Preferably, the grinding of the segments takes place together.

There are preferably no edges or steps that adversely affect the cutting result.

In this way, in particular a streaking when slicing products can be prevented.

According to a further embodiment, the, in particular differently formed, segments each comprise an RFID transponder, via which the segments of a rotary blade are assigned to one another.

In this way, even with segmented rotary blades, in particular with different cutting parameters, a pairing of the respective segments can be achieved. This allows in particular a uniform grinding process. It is also possible to ensure uniform balancing with the help of RFID transponders.

In particular, the respective segments may exhibit similar signs of wear, for which reason it may be advantageous for the respective segments of a rotary blade to always be ground in the same or at least similar intervals or always be used together during cutting operations.

Alternatively, however, it is basically possible to exchange individual, for example damaged, segments of a rotary blade. A newly selected pairing can also be stored on the RFID transponders.

In principle, any information carriers are conceivable instead of an RFID transponder. For example, the individual segments can also be assigned to each other in color. An assignment by means of barcodes or QR codes is basically possible.

The present disclosure also relates to a non-inventive method for grinding a sickle blade with at least two equal spirals. In particular, at least two, three, four, five or more identical spirals may be provided. The sickle blade is hereby integrally formed, i. not divided into individual segments.

The sickle knife can be used in particular for a machine for slicing food products, such as sausage, ham, cheese or the like. This may in particular be a high-performance slicer.

For grinding, a device for grinding is used.

First, the course of a cutting edge of at least one spiral is determined by means of a measuring device and then at least one spiral is subsequently ground during a relative movement between the spiral and a grinding tool.

The relative movement between the spiral and the grinding tool is controlled on the basis of the determined cutting profile. Equal spirals are successively ground on the basis of the cutting profile of a first spiral.

Preferably, therefore, first the cutting profile of the first spiral is determined. After that, in particular, the first spiral can be ground. Spirals, which are made equal to the first spiral, can then be ground on the basis of the data of the first spiral.

For example, if four spirals, each with two identically designed spirals, are provided, one respective cutting profile can be determined by the different spirals, which can be used to grind the respectively identically designed spirals.

Preferably, however, all the spirals of a sickle blade are made equal.

These can be ground in succession, wherein the edge profile determined by means of the first spiral can be used to control the relative movement between the grinding tool and at least one further spiral.

Therefore, it is not necessary to determine the cutting profile of each individual spiral. For identically executed spirals, a single determination of the cutting edge progression is sufficient.

According to one embodiment of the method according to the invention, in which rotary knives are ground with at least two spirals, one, in particular each, coupled to a respective spiral or a respective segment memory device and / or a memory device of the grinding device, preferably an RFID transponder, with data described. Alternatively or additionally, the data stored thereon can be read out.

Preferably, each spiral or each segment may comprise a memory device, in particular an RFID transponder or RFID chip. The storage device may in particular be attached to a side surface of the spiral or of the segment.

Basically, any storage media such as e.g. Chips, memory cards, flash memory, USB sticks or SSD memory possible. In principle, the data information can also be contained in barcodes or QR codes, which can be applied in particular to the spirals or the segments.

In particular, the data may include the course of the respective cutting edge or data dependent on this course, in particular cutting edge angles and / or cutting profiles. For example, the course of the cutting edge of the first spiral or of the first segment can be stored.

The data may, for example, represent the control data for the grinding tool.

The data may also include cutting parameters, such as cutting angle. In addition, the information can be included in the data, how often one corresponding spiral or a corresponding segment has already been ground. Also, for example, balance data of the respective spirals or segments can be stored. In particular, the data determined on the basis of the first spiral or of the first segment, which relate to the cutting profile of the first spiral or of the first segment, can be transmitted to the storage device of the grinding device and / or to the storage device of at least one further spiral or a further segment ,

In particular, each spiral or each segment may have its own memory device, preferably an RFID transponder or a chip. In particular, information which in particular contains the cutting parameters can thus be stored on each spiral or each segment.

Preferably, the cutting profile of a spiral or a segment is first determined. The spiral or the segment is then ground in particular. The determined data can then, at least in the meantime, be stored on the storage device of the spiral or of the segment and / or in the storage device of the grinding device.

In particular, e.g. another segment can be spanned one after the other or together with the first segment and ground on the basis of the data contained in the memory device of the first segment or the memory device of the grinding device, which serve as default values.

The data can then be transferred, in particular from the storage device of the grinding device, to the storage device of at least one further spiral or at least one further segment.

In this way, spirals or segments can contain information about the cutting edge, which were not measured themselves.

According to a further embodiment, the grinding of the respective spirals or segments is coordinated with each other. The grinding is particularly coordinated, i. not independent of each other.

The grinding may include a plurality of processing steps, in particular pre-grinding, grinding and / or regrinding. First, a processing step is performed on a first spiral or a first segment and then on at least one further spiral or a further segment. In particular, a further processing step is performed only after completion of a processing step.

In particular, first a first spiral or a first segment can be pre-ground. Subsequently, a second spiral or a second segment can be pre-ground. Then a first spiral or a first segment can be ground. Thereupon, the grinding of the second spiral or of the second segment can take place. Finally, a regrinding of the first spiral or the first segment can take place. Following this, regrinding of the second spiral or of the second segment can take place.

In this way it can be ensured that a possible wear of the grinding wheels only insignificantly influences the uniform grinding geometry, in particular the sharpness of the respective cutting edges.

All embodiments of the device described here are in particular designed to be operated according to the method described here. Furthermore, all embodiments of the device described here and all embodiments of the method described here can each be combined with each other.

Fig. 1

eine seitliche Ansicht einer erfindungsgemäßen Vorrichtung zum Schleifen von Rotationsmessern,

Fig. 2

eine seitliche Ansicht eines zwei Segmente umfassenden Rotationsmessers,

Fig. 3

eine seitliche Ansicht eines Rotationsmessers mit zwei Spiralen,

Fig. 4

eine seitliche Ansicht eines zwei Segmente umfassenden Rotationsmessers in separaten Aufnahmen,

Fig. 5

eine seitliche Ansicht einer Handhabungsvorrichtung,

Fig. 6

eine seitliche Ansicht eines drei Segmente umfassenden Rotationsmessers, und

Fig. 7

einen Querschnitt eines Segments gemäß Fig. 6.

The invention will now be described by way of example with reference to the drawings. Show it:

Fig. 1

a side view of a device according to the invention for grinding rotary blades,

Fig. 2

a side view of a two-segment rotary knife,

Fig. 3

a side view of a rotary knife with two spirals,

Fig. 4

a side view of a two-segment rotary knife in separate shots,

Fig. 5

a side view of a handling device,

Fig. 6

a side view of a three-segment rotary knife, and

Fig. 7

a cross-section of a segment according to Fig. 6 ,

In the Fig. 1 illustrated grinding device 1 is provided for grinding rotary blades 3 comprising several segments 2. Such rotary blades 3 are used, for example, in high-speed cutting machines for slicing food products, which are also referred to as slicers. In order to attach a segment 2 to be ground on the grinding device 1, a receptacle 5 is provided, on which a receiving opening 7 of the segment 2 is placed and on which the segment 2 is fastened (cf. Fig. 2 ).

The grinding device 1 has a grinding tool 9. The segment 2 and the grinding tool 9 are movable relative to one another so that a cutting edge 11 running on the circumference of the segment 2 can be ground by the grinding tool 9. Before the grinding takes place in the device 1, an automatic determination of the profile of the cutting edge 11 by a measuring device 13 which is coupled to a controller 15, so that the determined cutting profile of the controller 15 can be provided. The controller 15 is in turn coupled to the grinding tool 9 and a drive (not shown) for the receptacle 5. By the drive, the receptacle 5 and the attached segment 2 can be rotated in a direction of rotation I and the controller 15 is adapted to use the determined cutting edge for controlling the relative movement between the grinding tool 9 and the segment 2.

It can also be provided not to move the receptacle 5 and instead to move the grinding tool 9 in the x and y directions.

To detect the course of the cutting edge 11, the measuring device 13 has a forked light barrier 17, which is coupled to a linear motor (not shown) and arranged so that the forked light barrier 17 is located radially outside the cutting edge 11. By the linear motor, the fork light barrier 17 along a travel path II (see., The double arrow in Fig. 1 ) so that the forked light barrier 17 is moved toward or away from the segment 2.

The fork light barrier 17 has a detection range within which a light path between a transmitter and a receiver (both not shown) of the fork light barrier 17 extends. If the fork light barrier 17 is moved radially outwards onto the segment 2, the light path is interrupted by a section of a radially outer cutting edge 23 crossing the travel path II as soon as the section reaches the detection area. At opposite If the section leaves the detection area again, the light path is released again.

In the device 1, the segment 2 is rotated in the direction of rotation I, so that for a plurality of rotational positions of the segment 2 of the respective the path II of the forked light barrier 17 crossing portion of the cutting edge 23 can be detected. In this case, the respective position of the light barrier 17 relative to the travel path II, for example by means of an encoder coupled to the linear motor (FIG. 2), is measured as the measured value for the position of a detected section. not shown), determined by the measuring device 13. In addition, the measuring device 13 is designed to determine the respective position of the segment 2, based on the direction of rotation I, in which the respective section is detected. For this purpose, the measuring device 13 is coupled to a position sensor, not shown, which is designed and arranged to detect the position of the segment 2, for example. As a rotation angle relative to a zero point.

The measuring device 13 therefore determines a multiplicity of value pairs in the described embodiment. In this case, a pair of values comprises the position of the respective section II of the cutting edge 23 crossing the travel path II, as well as the associated rotational position of the segment 2, determined in relation to the travel path II. The pairs of values determined in this way can be assumed directly as the cutting edge profile. Alternatively, for each pair of values, the measured value, which indicates the position of a section relative to the travel path II, can be converted into a distance value which indicates the distance between the respective section and the center of the receptacle 5 or the receiving opening 7. Thus, the course of the cutting edge 23 in polar coordinates with the center of the receptacle 5 or the receiving opening 7 can be determined as the origin. Depending on the number of value pairs determined in this way, further value pairs can be calculated by interpolation.

Alternatively, the measuring device could be designed, for example, such that an edge 51 of the segment 2 extending in accordance with the cutting edge 11 is detected. It is also conceivable in principle to determine the cutting edge profile by means of a camera and by image evaluation. A relative movement between segment 2 and measuring device 13 is therefore not mandatory for the determination of the cutting edge profile.

The thus determined edge profile is transmitted by the measuring device 13 to the controller 15 and stored there at least temporarily in a memory 25. Also, the edge profile on an RFID transponder 26 of the segment 2 can preferably be stored permanently.

Instead of determining the edge profile via a measuring device 13, a cutting path already stored on the RFID transponder 26 or the memory 25 can be read out and used for grinding.

After determining the cutting edge profile, the forked light barrier 17 is moved away from the segment 2.

For grinding the segment 2, the cutting edge 11 is processed in a conventional manner by a grinding and Abziehscheibe 29, 31 of the grinding tool 9. The blade 11 is touched by the grinding wheel 29 in a grinding point and the Abziehscheibe 31 in a Abziehpunkt , The grinding tool 9 can be positioned relative to the segment 2 in such a way that, in particular during the entire grinding process, a pivot axis is aligned tangentially to the cutting edge 23 passing through the respective grinding point. The segment 2 is rotated in the direction of rotation I and thus moved past the grinding tool 9. The controller 15 is - as mentioned - adapted to the relative movement between the segment 2 and the grinding tool 9 to control so that the cutting edge 11 is "driven off" by the grinding tool 9 according to the determined cutting edge. In this case, the grinding tool 9 can be moved by means of a linear motor 55 along a travel path to keep the grinding point and the Abziehpunkt in contact with the cutting edge 11, while the segment 2 is moved past the grinding tool 9. The grinding tool 9 is thus traced in order to compensate for the changing radius of the segment 2.

For example, first a segment 2 can be placed on the receptacle 5. The measuring device 13 can then determine the course of the cutting edge 11. This history can be stored in the memory 25. Using the controller 15, the cutting edge 11 can now be ground with the grinding tool 9.

After completion of the grinding process, the segment 2 can be removed. Thereupon, a segment 2 of the same design can be placed on the receptacle 5. Since the course of the cutting edge 11 corresponds to the course of the previous segment, the data contained in the memory 25 can be used to control the grinding tool 9. A renewed measurement of the cutting profile can thus be omitted. The course of the cutting edge 11 can be stored on the RFID transponder 26 of the segment 2.

In this way, it is thus possible to easily grind a plurality of the same segments running in succession.

In Fig. 2 a rotary blade 3 with a spiral 57 is shown. In one-piece rotary blades 3 was previously an outlet 59 is necessary. Because the rotary blade 3 is divided into the segments 2, such an outlet 59 is no longer necessary. Thus, cutting edges 11 can be produced which have a greater circumferential length. Dashed is in Fig. 2 this one Cutting range of 360 ° shown. Dotted is a cutting area of greater than 360 ° shown.

The individual segments 2 can thus successively on the receptacle 5 of the grinding device 1 according to Fig. 1 be put on. An outlet 59 is unnecessary here.

Each segment 2 can have an RFID transponder 26, to which various data, for example a cutting profile, a cutting angle, the number of grinding passes already made or data with which the segments 2 can be assigned to one another, are stored.

Each segment 2 also comprises recesses 61. These can serve, for example, for mounting and / or centering on a blade receptacle, in particular a slicing device, or on a handling device. Also, for example, a counterweight 61 may be attached to the recesses 61.

In Fig. 3 a rotary blade 3 with two spirals 57 is shown. The rotary blade 3 is in this case integrally formed, that is not divided into segments. Also, such a rotary blade 3 can with a grinding device according to Fig. 1 be sanded. The rotary blade 3 can in this case be placed on the receptacle 5 via the receiving opening 7. Subsequently, for example, the course of a cutting edge 11 of one of the spirals 57 can be determined. This course can be stored, for example, on the RFID transponder 26.

On the basis of the determined cutting profile, both spirals 57 can now be ground. A separate determination of the cutting edge profile for both identically formed spirals 57 is thus not necessary.

In Fig. 4 a rotary blade 3 is shown, which is divided into two segments 2. The segments 2 are placed on different receptacles 5. The segments 2 can, for example, together with a grinding device 1 according to Fig. 1 be sanded, which includes two receptacles 5 accordingly. It is conceivable here that the receptacles 5 are already spaced from each other by design. Alternatively, it is also possible that the receptacles 5 are initially arranged next to one another. In this position, the segments 2 can be placed. Subsequently, the receptacles 5 can be adjusted relative to each other along an adjustment path III shown as a double arrow, so that the segments 2 are spaced from each other. In this spaced position no outlet 59 is necessary. Thus, cutting areas of 360 ° can be achieved.

In Fig. 5 a handling device 63 with two sections 65 is shown. The sections 65 are for receiving segments 2 of a knife 3 according to Fig. 4 educated.

The contour of the individual sections 65 is in each case adapted to the contour of the individual segments 2 of the blade 3. The sections 65 have different radii.

Each section comprises a cutting receptacle 67, in which the cutting edges 11 of the segments 2 can be accommodated. Furthermore, each section 65 comprises two handles 69 and screws 71.

The sections 65 can be placed individually on the segments 2 for disassembly of a knife 3. By means of the screws 71, which can engage in recesses 61 of the segments 2, the segments 2 can be attached to the respective sections 65. The segments 2 are then released from the receptacle 5 and can with the help of pieces 65 on the handles 69th be removed and transported. The sections 65 may be interconnected by means of a composite device 73, such as a detent, screw, clamp and / or slide device. The sections 65 can thus be connected in particular releasably to each other.

In Fig. 6 a rotary blade 3 with three segments 2 is shown. Dashed is a cutting area of 360 ° and dotted by greater than 360 ° shown.

The individual segments 2 can be ground sequentially or together.

The grinding can e.g. be made such that the cutting edges 11 of the respective segments 2 have different cutting angle. The cutting edges 11 may have a steadily increasing cutting angle, for example.

It is also possible that each of the segments 11 has a constant cutting angle. For example, the segment 11 shown on the left side may have a cutting angle of 15 °, the middle segment 11 a cutting angle of 20 ° and the segment 11 shown on the right a cutting angle of 25 °.

In a transition region 75, the cutting angle can be adapted to each other here, so that a smooth transition is ensured. The cutting edge 11 of at least one segment 2 can in this case be adapted to the cutting edge 75 of the cutting edge 11 of the adjacent segment 2. This is based on the dashed line in Fig. 7 shown in which a cross section of a segment 2 is shown.

At the transition region 75, the cutting edge 11 can thus have a cutting angle different from the remaining cutting edge 11 of the segment 2.

Also, the cutting angle of the blades 2 of the rotary blade 3 according to Fig. 2 can be variable, especially steadily increasing, be designed. Also mutually different cutting angle of the individual segments 2, for example 15 ° and 20 °, are possible in this case. The transition region 75 can be smoothed.

Segmented rotary blades, in particular with variable cutting angles and / or large peripheral lengths, can therefore also be ground in accordance with the invention.

LIST OF REFERENCE NUMBERS

1

grinder

2

segment

3

rotary knife

5

admission

7

receiving opening

9

grinding tool

11

cutting edge

13

measuring device

15

control

17

Light barrier

23

cutting edge

25

Storage

26

RFID transponder

29

grinding wheel

31

honing

51

edge

55

linear motor

57

spiral

59

outlet

61

recess

63

handling device

65

section

67

cutter reception

69

handle

71

screw

73

composite device

75

Transition area

I

direction of rotation

II

traverse

III

adjustment

Claims (14)

1. An apparatus for grinding rotary blades (3) which have at least two segments (2), in particular scythe-like blades or circular blades, in particular for a machine for slicing food products, comprising

   - at least two receivers (5) to each of which a segment (2) is attachable;

   - at least one grinding tool (9), wherein the grinding tool (9) and the segment (2) attached in the respective receiver (5) are movable relative to one another such that a blade edge (11) extending at the periphery of the segment (2) can be ground by the grinding tool (9);

   - a measuring device (13) for determining the extent of the blade edge (11) of at least one segment (2); and

   - a control (15) which is configured to use the determined blade edge extent to control a relative movement between the grinding tool (9) and at least one segment (2),

   - wherein a separate receiver (5) is provided for each segment (2), with the receivers (5) and/or the segments (2) held in the receivers (5) being spaced apart from one another on grinding.
2. An apparatus in accordance with claim 1,
   characterized in that,
   with segments (2) of the same design, the control (15) is configured to use, at least in part, the blade edge extent determined with reference to a first segment (2) to control the relative movement between the grinding tool (9) and at least one further segment (2).
3. An apparatus in accordance with claim 1 or claim 2,
   characterized in that
   a reading and/or writing device is provided which is configured to write data to a memory device, in particular to each memory device (26), coupled to a respective segment (2) and/or to read the data stored thereon.
4. An apparatus in accordance with any one of the preceding claims,
   characterized in that
   a reading and/or writing device is provided which is configured to write data to a memory device of the grinding apparatus (25) and/or to read the data stored thereon.
5. An apparatus in accordance with any one of the preceding claims,
   characterized in that
   the receivers (5) are associated with one another and/or are adjustable relative to one another.
6. A method of grinding rotary blades (3) which have at least two segments (2), in particular scythe-like blades or circular blades, in particular for a machine for slicing food products, using an apparatus (1) in accordance with any one of the preceding claims, in which
   the extent of a blade edge (11) of at least one segment (2) is determined and at least one segment (2) is subsequently ground during a relative movement between the segment (2) and a grinding tool (9),
   wherein the relative movement between the segment (2) and the grinding tool (9) is controlled with reference to the determined blade edge extent, wherein the segments (2) are held at different receivers (5) which are adjusted relative to one another to provide a spacing between the segments (2) during the determination of the blade edge extent and/or during the grinding.
7. A method in accordance with claim 6,
   characterized in that
   segments (2) of the same design are ground after one another, with the blade edge extent determined with reference to a first segment (2) being used, at least in part, to control the relative movement between the grinding tool (9) and at least one further segment (2).
8. A method in accordance with claim 6,
   characterized in that
   differently configured segments (2) are each ground using different grinding parameters.
9. A method in accordance with claim 8,
   characterized in that
   the differently configured segments (2) are ground such that they each have a blade edge angle varying, in particular continuously increasing or decreasing, in the peripheral direction.
10. A method in accordance with claim 8,
    characterized in that
    the differently configured segments (2) are ground such that they have blade edge angles which differ from one another and which are at least substantially constant within a respective segment (2), with the blade edge angle in a transition region between the segments (2) in particular differing from blade edge angles in other regions of the segments (2), with a gentle transition being ground between the segments (2).
11. A method in accordance with any one of the claims 6 to 10,
    characterized in that
    the segments (2) each comprise an RFID transponder (26) via which the segments (2) of a rotary blade (3) are associated with one another.
12. A method in accordance with any one of the claims 6 to 11,
    characterized in that
    data are written to a memory device, in particular to each memory device (26), coupled to a respective spiral (57) / to a respective segment (2) and/or the data stored on said memory device are read.
13. A method in accordance with any one of the claims 6 to 12,
    characterized in that
    data are written to a memory device (25) of the grinding apparatus (1) and/or the data stored thereon are read.
14. A method in accordance with any one of the claims 6 to 13,
    characterized in that
    the grinding comprises a plurality of processing steps, in particular a rough grinding, a grinding and/or a regrinding; and in that a processing step is first carried out at a first spiral (57) or at a first segment (2) and subsequently at at least one further spiral (57) or at a further segment (2); and in that a further processing step is in particular only carried out after a processing step has been completed.

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